离子镀过程中基体“热影响区”的演变及其对镀层的影响

Evolution of Substrate "Heat Affected Zone" in Ion Plating and Its Effect on Coatings

以淬火态40Cr Ni Mo A为基材,研究了靶功率密度对"热影响区"升温幅度、区域尺度及镀层结构的影响规律。结果表明,随着靶功率密度从20.61 W/cm^2提高到143.01 W/cm^2,不仅与镀层比邻的基体温度从310℃升高到525℃、"热影响区"的尺度从0.37 mm增加到2.51 mm,而且纯Ti镀层的择优取向由(002)转变为(110),平均晶粒尺寸由9.9 nm增大至19.5 nm,表面粗糙度先减小后增大。同时,当基体温度大于300℃时,镀层的内应力随着晶格微观缺陷的消除而释放。

In the process of depositing coatings on the surface of metal substrates via ion plating, substrate temperature increases due to the bombardment of deposited particles and the heat radiation of discharge target, forming ＂heat affected zone＂ where substrate temperature gradually reduces from the surface. In this work, quenched 40CrNiMoA was prepared as substrate to discuss about the influence of target power density on the temperature rising range, region scale of ＂heat affected zone＂ and microstruc- ture of Ti coating. The results show that the traditional metal heat treatment method can accurately char- acterize temperature rising range and region scale of ＂heat affected zone＂. And, with target power density increases from 20.61 W/cm2to 143.01 W/cm2, substrate temperature ranges from 310 ℃ to 525 ℃, the re- gion scale of ＂heat affected zone＂ reaches to 2.51 mm. Also, the preferential orientation of Ti coating changes from （002） to （110）, the average grain size significantly increases from 9.9 nm to 19.5 nm, the surface roughness declines first and then increases slightly. In addition, the internal stress releases grad- ually for elimination of lattice defects when substrate temperature is above 300 ℃. KEY WORDS ion plating, heat affected zone, Ti coating, microstructure, internal stress